CN110545483A

CN110545483A - Method, device and storage medium for playing media file by switching resolution in webpage

Info

Publication number: CN110545483A
Application number: CN201810532424.0A
Authority: CN
Inventors: 银国徽
Original assignee: Beijing ByteDance Network Technology Co Ltd
Current assignee: Douyin Vision Co Ltd; Douyin Vision Beijing Co Ltd
Priority date: 2018-05-29
Filing date: 2018-05-29
Publication date: 2019-12-06
Anticipated expiration: 2038-05-29
Also published as: CN110545483B; US20200396504A1; JP7008829B2; JP2021508891A; WO2019227738A1; US10924801B2

Abstract

The present disclosure provides a method for playing media files by switching resolutions in a webpage, which includes: receiving a resolution switching event when a player embedded in a webpage plays an original resolution media file; responding to a resolution switching event, and requesting media data in a target resolution media file to be switched; wherein, the original resolution media file and the target resolution media file adopt a non-streaming media packaging format; constructing a segmented media file for independent decoding based on the requested media data; and sending the segmented media file to the media element of the webpage through a media source expansion interface of the webpage, wherein the segmented media file is used for playing the media element at a playing point when a resolution switching event occurs. The disclosure also provides a device and a storage medium for playing the media file by switching the resolution in the webpage.

Description

method, device and storage medium for playing media file by switching resolution in webpage

Technical Field

the present disclosure relates to multimedia technologies, and in particular, to a method and an apparatus for playing a media file in a webpage with a resolution being switched, and a storage medium.

Background

The Moving Picture Experts Group (MPEG) -4 format is a container format widely used at present, and can store video data and audio data in a plurality of encoding modes.

The embedded player of the browser plays the media file through the webpage of the browser or the webpage of an Application program (APP) embedded in the browser kernel by using the HyperText Markup Language (HTML) 5 media element playing of the browser, however, the related art can only provide the playing support for the streaming media file, and for the MP4 file in the network, because the file is not in the streaming media format, unless the format conversion is performed in advance, the player cannot play the streaming media mode of the media file through the APP embedded in the browser or the browser kernel, and at the same time, the resolution is switched.

For example, related technologies employ converting MP4 files into Streaming media formats, such as flv (flash video), hypertext transfer protocol Live Streaming (HLS, HTTP Live Streaming), etc., however, content providers still store original MP4 files, so as to trace back in time when playing Streaming media format files is problematic, and store MP4 files and transcoded files at the same time, the storage space occupied by MP4 file services grows exponentially, and the storage space deployment and complexity of Streaming media services significantly increase.

disclosure of Invention

in view of this, the embodiments of the present disclosure provide a method, an apparatus, and a storage medium for playing a media file by switching resolutions in a web page, which can play a non-streaming format media file through the web page, and overcome a limitation that a non-streaming format media file can be independently played only after being completely downloaded.

The embodiment of the disclosure provides a method for playing a media file by switching resolution in a webpage, which comprises the following steps: receiving a resolution switching event when a player embedded in a webpage plays an original resolution media file; responding to the resolution switching event, and requesting media data in a target resolution media file to be switched; wherein, the original resolution media file and the target resolution media file adopt a non-streaming media packaging format; constructing a segmented media file for independent decoding based on the requested media data; and sending the segmented media file to a media element of the webpage through a media source expansion interface of the webpage, wherein the segmented media file is used for playing the media element at a playing point when the media element is connected with the resolution switching event.

the embodiment of the present disclosure provides a device for switching resolution to play a media file in a web page, including: the event receiving module is used for receiving a resolution switching event when the player embedded in the webpage plays the original resolution media file; the data request module is used for responding to the resolution switching event and requesting the media data in the target resolution media file to be switched; a segment construction module for constructing a segmented media file for independent decoding based on the requested media data; and the media playing module is used for sending the segmented media file to the media element of the webpage through a media source expansion interface of the webpage, wherein the segmented media file is used for playing the media element at a playing point when the media element is connected with the resolution switching event.

In another aspect, an embodiment of the present disclosure further provides an apparatus for switching resolution to play a media file in a web page, including:

A memory for storing executable instructions;

And the processor is used for executing the executable instructions stored in the memory to realize the method for playing the media file in the webpage by switching the resolution, which is provided by the embodiment of the disclosure.

In another aspect, the present disclosure also provides a storage medium storing executable instructions, where the executable instructions are used to implement the method for playing a media file in a webpage with a switching resolution provided by the present disclosure.

the embodiment of the disclosure has the following technical effects:

1) the media data in the media file in the non-streaming media format is converted into the segmented media file, and the segmented media file is sent to the media element of the webpage for decoding and playing through the media source expansion interface of the webpage, so that the media file in the non-streaming media format is played through the webpage, and the limitation that the file in the non-streaming media packaging format can be independently played after being completely downloaded is overcome.

2) The conversion of the media data to the segmented media file is completed by the player at the front end, the media files with different resolutions are required to be stored for the background server, and the segmented media file is not required to be stored in advance at the server side, so that the media file is played in a low storage space occupation mode.

3) The media files which do not support the streaming media playing are converted into the segmented media files which support the streaming media format for playing, when the resolution ratio is switched, the media files with the target resolution ratio do not need to be downloaded again, so that the pictures can be switched seamlessly, the phenomenon of black screen is avoided, and the smooth playing of the media files is realized.

drawings

Fig. 1 is a schematic diagram of an alternative structure of a container for multimedia file encapsulation provided by an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of an alternative package structure of an MP4 file according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of an alternative structure of a media data container for storing media data in a media file according to an embodiment of the disclosure;

FIG. 4 is a schematic diagram of an alternative packaging structure of an FMP4 file in an embodiment of the present disclosure;

FIG. 5 is a schematic diagram illustrating an alternative configuration of an apparatus for playing media files with different resolutions in a web page according to an embodiment of the disclosure;

FIG. 6 is a schematic diagram illustrating an alternative configuration of an apparatus for playing media files with different resolutions in a web page according to an embodiment of the disclosure;

Fig. 7 is an alternative flowchart of a method for playing a media file in a webpage with a resolution being switched according to an embodiment of the present disclosure;

FIG. 8 is an alternative flow diagram of packaging segmented media files provided by examples of the present disclosure;

FIG. 9 is an alternative diagram of a player according to an embodiment of the present disclosure playing a segmented media file through a media source extension interface of a web page;

FIG. 10 is a schematic diagram of an MP4 file being converted into an FMP4 file and being played through a media source extension interface according to an embodiment of the present disclosure;

fig. 11 is an optional flowchart of the play control method according to the embodiment of the disclosure.

Detailed Description

For the purpose of making the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be described in further detail with reference to the accompanying drawings, the described embodiments should not be construed as limiting the present disclosure, and all other embodiments obtained by a person of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure.

Before the present disclosure is explained in further detail, terms and expressions referred to in the embodiments of the present disclosure are explained, and the terms and expressions referred to in the embodiments of the present disclosure are applied to the following explanations.

1) a media file storing a file of encoded media data (e.g., at least one of audio data and video data) in a container (Box), which further includes metadata to express media information to ensure that the media data is correctly decoded.

for example, a formed media file in which media data is packaged in a Moving Picture Experts Group (MPEG) -4 packaging format is called an MP4 file. Typically, the MP4 file stores therein Video data encoded by the Advanced Video Coding (AVC, h.264) or MPEG-4(Part 2) specification and Audio data encoded by the Advanced Audio Coding (AAC) specification, although other encoding schemes for Video and Audio are not excluded.

2) The container (Box), also called a Box, an object-oriented component defined by a unique type identifier and a length, see fig. 1, is an optional structural diagram of the container provided by the embodiment of the present disclosure, and includes a container Header (Box Header) and container Data (Box Data), which are filled with binary Data for expressing various information.

the container header includes a size (size) and a type (type), the size indicates a length occupied by the container in the media file, the type indicates a type of the container, and referring to fig. 2, the container is an optional packaging structure diagram of the MP4 file provided by the embodiment of the present disclosure, and the basic container types referred to in the MP4 file include a file type container (ftyp box), a metadata container (moov box), and a media data container (mdat box).

The container data portion may store specific data, where the container is referred to as a "data container," and may further encapsulate other types of containers, where the container is referred to as a "container of a container.

3) a Track (Track), also called a Stream (Stream), a time-ordered sequence of related samples (Sample) in a container of media data, a Track representing a sequence of video frames or a sequence of audio frames for media data, and possibly a subtitle Track synchronized with the sequence of video frames, a set of consecutive samples in the same Track being called a Chunk (Chunk).

4) A file type container, a container for storing the capacity (i.e. the length of occupied bytes) and the type of a file in a media file, as shown in fig. 2, the file type container is marked as "ftyp box", wherein the stored binary data describes the type and compatibility of the file according to the specified byte length.

5) a metadata container, a container in a media file for storing metadata (i.e., data describing multimedia data stored in the media data container), and information expressed by binary data stored in the metadata container in the MP4 file are referred to as media information.

As shown in fig. 2, the header of the metadata container represents the type of the container as "moov box" using binary data, and the container data part encapsulates an mvhd container for storing general information of an MP4 file, is independent of an MP4 file, and is related to the playing of an MP4 file, including a time length, a creation time, a modification time, and the like.

The media data container of the media file may include sub-containers corresponding to a plurality of tracks, such as an audio track container (audio track box) and a video track container (video track box), in which references and descriptions of media data of the corresponding tracks are included, and the necessary sub-containers include: a container (denoted tkhd box) for describing the characteristics and overall information of the track (e.g. duration, width, height), and a container (denoted mdia box) for recording media information of the track (e.g. information of media type and sample).

As for the sub-containers packaged in the mdia box, it may include: recording the relevant attributes and content of the track (denoted mdhd box), recording the playing procedure information of the media (denoted hdlr box), describing the media information of the media data in the track (denoted minf box); the minf box in turn has a sub-container (denoted as dinf box) for explaining how to locate the media information, and a sub-container (denoted as stbl box) for recording all the time information (decoding time/display time), position information, codec etc. of the samples in the track.

referring to fig. 3, which is a schematic structural diagram of a media data container in a media file for storing media data provided by the embodiment of the present disclosure, the time, type, capacity and location of a sample in the media data container can be interpreted by using media information identified from binary data in a stbl box, and each sub-container in the stbl box is explained below.

The stsd box contains a sample description (sample description) table, and there may be one or more description tables in each media file according to different coding schemes and the number of files storing data, and the description information of each sample can be found through the description tables, and the description information can ensure correct decoding of the sample, and different media types store different description information, for example, the description information is the structure of the image in the case of video media.

The stts box stores the duration information of the samples and provides a table to map time (decoding time) and the serial numbers of the samples, and the samples at any time in the media file can be located through the sttx box; the stts box also uses other tables to map the sample size and pointers, where each entry in the table provides the serial number of consecutive samples within the same time offset and the offset of the sample, and increments these offsets to build a complete time-sample mapping table, and the calculation formula is as follows:

DT(n+1)＝DT(n)+STTS(n) (1)

Where STTS (n) is the duration of the nth sample, DT (n) is the display time of the nth sample, the samples are arranged in a time sequence, such that the offset is always non-negative, DT generally starts with 0, and the calculation formula is as follows, taking the display time DT (i) of the ith sample as an example:

DT(i)＝SUM(for j＝0 to i-1 of delta(j)) (2)

The sum of all offsets is the duration of the media data in the track.

The stss box records the sequence number of the key frame in the media file.

The sts box records the mapping relation between the samples and the blocks for storing the samples, the relation between the serial numbers of the samples and the serial numbers of the blocks is mapped through a table, and the blocks containing the specified samples can be found through table lookup.

The stco box defines the position of each block in the track, expressed in terms of the offset of the starting byte in the media data container, and the length (i.e., the size) relative to the starting byte.

The stsz box records the size (i.e., size) of each sample in the media file.

6) Media data container, a container for storing multimedia data in a media file, for example, a media data container in an MP4 file, as shown in fig. 3, a sample is a unit stored in the media data container, and is stored in a block of the media file, and the lengths of the block and the sample may be different.

7) and segmenting the media files, wherein the media files are divided into subfiles, and each segmented media file can be independently decoded.

Taking an MP4 file as an example, media data in an MP4 file is divided according to key frames, the divided media data and corresponding metadata are packaged to form a segmented MP4(FMP4, Fragmented MP4) file, and metadata in each FMP4 file can ensure that the media data is correctly decoded.

For example, when the MP4 file shown in fig. 2 is converted into multiple FMP4 files, referring to fig. 4, which is an optional packaging structure diagram of FMP4 files provided in the embodiment of the present disclosure, one MP4 file may be converted into multiple FMP4 files, and each FMP4 file includes three basic containers: moov containers, moof containers, and mdat containers.

The moov container includes MP4 file level metadata describing all media data in the MP4 file from which the FMP4 file is derived, such as the duration, creation time, and modification time of the MP4 file.

the moof container stores segment-level metadata describing media data packaged in the FMP4 file where it is located, ensuring that the media data in the FMP4 can be decoded.

The 1 moof container and the 1 mdat container constitute 1 segment of the segment MP4 file, and 1 or more such segments may be included in the 1 segment MP4 file, and the metadata encapsulated in each segment ensures that the media data encapsulated in the segment can be independently decoded.

8) Media resource Extensions (MSE) interface, player-oriented interface implemented in web pages, interpreted by the browser's interpreter during loading in the web page, implemented by executing a front-end programming language (e.g., JavaScript), provides the player with the functionality to call the play Media stream of hypertext markup language (HTML) Media elements (Media elements), for example, to implement the play functionality of video/audio using video Element < video > and audio Element < audio >.

9) The streaming media format encapsulates media data into a media file of the streaming media, and the media file can be decoded and played without complete downloading and extra transcoding, namely, native support is provided for an encapsulation technology of downloading and playing simultaneously. A typical file in streaming media format includes: TS media file fragments based on HTTP Live Streaming (HLS, HTTP Live Streaming) technology, FLV (flash video) files, and the like.

10) Non-streaming media format, which is a packaging technique that packages media data into media files and the media files can be decoded and played after being completely downloaded, a typical file in non-streaming media format includes: MP4 files, Windows Media Video (WMV) files, Advanced Streaming Format (ASF) files, and the like.

It should be noted that the MP4 file does not natively support streaming media format playback, but the technical effect of playing while downloading can be achieved by filling invalid binary data into the transcoded media stream of the player after online transcoding or the missing part of the partially downloaded MP4 file (for example, in the case of full downloading of ftyp container and moov container, the missing part of the mdat container is replaced by invalid binary data).

First, a device for playing a media file by switching resolution in a web page according to an embodiment of the present disclosure is described, where the device for playing a media file by switching resolution in a web page may be provided as hardware, software, or a combination of hardware and software.

referring to fig. 5, fig. 5 is an optional schematic diagram of an apparatus for switching resolution to play a media file in a web page according to an embodiment of the present disclosure, where the apparatus 500 for switching resolution to play a media file in a web page may be a mobile phone, a computer, a notebook computer, a tablet device, a personal digital assistant, and the like with a video playing function. The apparatus 500 for playing a media file in a web page with a resolution being switched shown in fig. 5 comprises: at least one processor 501, memory 502, at least one network interface 504, and a user interface 503. The various components of the apparatus 500 for playing media files at switched resolutions in a web page are coupled together by a bus system 505. It is understood that the bus system 505 is used to enable connection communications between these components. The bus system 505 includes a power bus, a control bus, and a status signal bus in addition to a data bus. For clarity of illustration, however, the various buses are labeled as bus system 505 in FIG. 5.

The user interface 503 may include a display, a keyboard, a mouse, a trackball, a click wheel, a key, a button, a touch pad, a touch screen, or the like, among others.

It will be appreciated that the memory 502 can be either volatile memory or nonvolatile memory, and can include both volatile and nonvolatile memory. The nonvolatile Memory may be a Read Only Memory (ROM), a Programmable Read Only Memory (PROM), an Erasable Programmable Read-Only Memory (EPROM), an Electrically Erasable Programmable Read-Only Memory (EEPROM); the magnetic surface storage may be disk storage or tape storage. Volatile Memory can be Random Access Memory (RAM), which acts as external cache Memory. By way of illustration and not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM). The memory 502 described in embodiments of the present disclosure is intended to comprise these and any other suitable types of memory.

The memory 502 in the disclosed embodiments includes, but is not limited to: the tri-state content addressable memory, static random access memory, is capable of storing media file data retrieved from the server to support the operation of the apparatus 500 for switching resolution to play media files in a web page. Examples of such data include: any computer program operating on the apparatus 500 for switching resolution to play a media file in a web page, such as the operating system 5021 and the application programs 5022; various types of media file data information, etc. The operating system 5021 includes various system programs, such as a framework layer, a core library layer, a driver layer, and the like, for implementing various basic services and processing hardware-based tasks. The application 5022 may comprise various applications, such as a client with the function of playing media files in web pages with switched resolutions, or an application. The program for implementing the method for switching the resolution to play the media file in the web page according to the embodiment of the present disclosure may be included in the application 5022.

The method disclosed by the embodiment of the disclosure is implemented by the processor 501. The processor 501 may be an integrated circuit chip having signal processing capabilities. In the implementation process, the method for playing the media file in the webpage by switching the resolution provided by the embodiment of the present disclosure may be completed through an operation in the form of a hardware integrated logic circuit or software in the processor 501. The Processor 501 may be a general purpose Processor, a Digital Signal Processor (DSP), or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, etc. The processor 501 may implement or perform the methods, steps, and logic blocks provided in the embodiments of the present disclosure. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of the method provided by the embodiments of the present disclosure may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium located in the memory 502, and the processor 501 reads information in the memory 502 and, in combination with hardware thereof, completes a method for playing a media file by switching resolutions in a web page.

In an exemplary embodiment, the disclosed embodiments also provide a computer-readable storage medium, such as the memory 502, comprising a computer program, which is executable by the processor 501 of the apparatus 500 for playing media files at a switching resolution in a web page, so as to implement a method for playing media files at a switching resolution in a web page. The computer readable storage medium can be Memory such as FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface Memory, optical disk, or CD-ROM; or may be a variety of devices including one or any combination of the above memories, such as a mobile phone, computer, tablet device, personal digital assistant, etc.

The following describes a pure hardware implementation of the apparatus for playing media files with a resolution switched in a web page, where the apparatus for playing media files with a resolution switched in a web page according to the embodiment of the present disclosure may be implemented by one or more Application Specific Integrated Circuits (ASICs), DSPs, Programmable Logic Devices (PLDs), Complex Programmable Logic Devices (CPLDs), Field Programmable Gate Arrays (FPGAs), or other electronic components, and is used to implement the method for playing media files with a resolution switched in a web page according to the embodiment of the present disclosure.

The following describes a pure software implementation of the apparatus for playing media files by switching resolutions in a web page, and the apparatus for playing media files by switching resolutions in a web page according to the embodiments of the present disclosure may be implemented by an application program or a plug-in, or by a combination of the two.

As an example, the application program may be a client dedicated to playing the media file in the resolution switched web page, or may be a client that takes the function of playing the media file in the resolution switched web page as an optional function and is implemented by installing a corresponding plug-in.

As an example, the plug-in may be implemented as a function upgrade installation package of an application program, and superimposes a function of switching resolution to play a media file in a web page in the application program for media playing; the elements in the webpage of the media playing can also be realized by adopting a front-end language, and the functions of switching the resolution to play the media file and playing the media in the webpage are realized in the webpage by being directly interpreted and executed by a browser.

as an example of a hardware implementation or a software implementation of the apparatus for playing a media file by switching resolution in a web page, the apparatus for playing a media file by switching resolution in a web page may be provided as a series of modules having a coupling relationship at a signal/information/data level, which will be described below with reference to fig. 6, see fig. 6, where fig. 6 is an optional schematic composition diagram of the apparatus for playing a media file by switching resolution in a web page according to the embodiment of the present disclosure, and shows a series of modules included in the apparatus for playing a media file by switching resolution in a web page, but the module structure of the apparatus for playing a media file by switching resolution in a web page is not limited to that shown in fig. 6, and for example, the modules therein may be further split or combined according to different functions implemented. The following describes functions implemented by the modules shown in fig. 6.

The event receiving module 601 is configured to receive a resolution switching event when the player embedded in the web page plays the original resolution media file.

a data requesting module 602, configured to request media data in a target resolution media file to be switched in response to the resolution switching event.

The data request module 602 is configured to determine two key frames in the target resolution media file based on the time of the video frame represented by the media information of the target resolution media file; decoding time of the two key frames is end point time of a given time interval, and the given time interval is used for continuing a playing point of the original resolution file; the data requesting module 602 is configured to request media data in the target-resolution media file based on a location of the media data represented by the media information in the target-resolution file, where a decoding time of the requested media data is located in the given time period.

A segment construction module 603 for constructing a segmented media file for independent decoding based on the requested media data.

A media playing module 604, configured to send the segmented media file to the media element of the web page through a media source extension interface of the web page, where the segmented media file is used for playing the media element at a playing point when the media element continues the resolution switching event.

Wherein the duration of the given time period is less than or equal to a pre-loaded duration, and the pre-loaded duration is less than the play duration of the target resolution media file.

in some embodiments, the segment constructing module 603 is configured to calculate metadata corresponding to the media data, where the calculated metadata carries media information for supporting decoding of the media data; and the segmentation construction module is used for filling the calculated metadata and the media data between the two key frames into an encapsulation structure of the segmented media file to obtain the corresponding segmented media file.

In some embodiments, the event receiving module 601 is configured to add the constructed segmented media file to a media source object in a media resource extension interface; the event receiving module 601 is configured to create a virtual address corresponding to the media source object; the event receiving module 601 is configured to transmit the virtual address to the media element of the web page, where the virtual address is used for the media element to play with the media source object as a data source.

In some embodiments, the media playing module 604 is further configured to, when the resolution switching event is received, continue playing the segmented media file based on the original resolution until the segmented media file with the target resolution is constructed by the segmented construction module and is sent by the media playing module 604 through the media source extension interface. Therefore, when the resolution ratio is switched, the player can continue to play the segmented media file based on the original resolution ratio, the blocking and the picture loss of the media file played by switching the resolution ratio in the webpage caused by switching the resolution ratio are avoided, and the user experience is improved.

In some embodiments, the player requests media data in a target resolution media file to be switched in response to a resolution switch event and constructs the requested media data into a corresponding independently decodable segmented media file. Referring to fig. 7, fig. 7 is an alternative flowchart of a method for switching resolution to play a media file in a web page according to an embodiment of the present disclosure, which will be described with reference to the steps shown in fig. 7.

in some of the examples described below, the media file is illustrated as MPEG-4, and implementations in other non-streaming media formats are readily envisioned in accordance with MPEG-4 implementations.

Step 701, when the player embedded in the web page plays the original resolution media file, a resolution switching event is received.

Step 702, the player responds to the resolution switching event and requests the media data in the target resolution media file to be switched. Wherein the original resolution media file and the target resolution media file are in a non-streaming media packaging format.

The player sends a network request for media data in the media file to the server.

in some embodiments, the player may send a network request for media data in the media file to the server by:

Determining two key frames in the media file to be played based on real-time playing points in the playing process of the media file; and sending a network request to a server, wherein the network request is used for requesting to acquire the media data between the two key frames in the media file.

The determination of two key frames based on the play point is explained. In the process of playing the media file, the player loads the data between the key frames to realize the playing of the media file, namely, the player takes the media data between the two key frames as a playing loading unit. As for the play point, it may be a play time that is reached by continuously playing the media file (i.e., naturally playing without user intervention), for example, from a play point of 30 th minute to a play point of 40 th minute; or, the media file may reach the playing time of the media file by means of jumping (i.e., the user clicks the progress bar through the cursor to realize page jumping), where for example, the original playing point is 20% of the playing progress, and the jumping playing point is 30% of the playing progress.

In practical applications, the two key frames determined based on the playing point may be two adjacent key frames in the media file, or one or more other key frames exist between the two key frames, and the number of the key frames between the two key frames may be determined according to the cache performance (such as the available cache capacity) of the browser, the network performance (network bandwidth), and the like, and may also be set according to actual needs.

In some embodiments, a manner of determining two key frames (set as a first key frame and a second key frame after the first key frame in decoding time) is described according to a case where a video frame corresponding to a playback point is a normal frame or a key frame, for a case where the playback point is a playback time that arrives by continuously playing a media file.

Case 1) the video frame corresponding to the playing point is a normal frame, and since the player uses the media data between two key frames as a basic playing loading unit, the media data after the playing point and before the first key frame (the key frame whose decoding time is later than the decoding time of the key frame of the playing point and closest to the playing point) after the playing point is the loaded media data, and in order to avoid repeatedly acquiring the loaded media data, the first key frame in the two key frames at a given time interval is: the first key frame of the media file with the decoding time after the playing point; the second key frame of the two key frames is: key frames in the media file that are decoded later in time than the first key frame.

Case 2) the video frame corresponding to the playing point is a key frame, and the first key frame of the two key frames is: the key frame corresponding to the playing point, namely the key frame aligned with the playing point in time; the second key frame of the two key frames is: key frames in the media file that are decoded later in time than the first key frame.

In case 1), the key frame crossing the playing point is used as the end point of the media data, so that it can be ensured that the video frame corresponding to the playing point has enough information for correct decoding, and frame skipping due to lack of decoded data (i.e. key frame) does not occur.

In another embodiment, the manner of determining two key frames (a first key frame and a second key frame after the first key frame in decoding time) is described according to the case that the video frame corresponding to the play point is a normal frame or a key frame, for the case that the play point is the play time that arrives by means of jumping.

Case 1) the video frame corresponding to the play point is a normal frame, and since the play point is reached by jumping, the first key frame before the play point and the media data between the play point are not loaded, and the first key frame is: searching a key frame with decoding time earlier than the starting time of a given period and closest to the starting time in the first key frame before a playing point in the media file, namely the time of media data (namely, the corresponding relation between the sequence number represented by the media information and the decoding time of the frame); the second key frame of the two key frames is: key frames in the media file that are decoded later in time than the first key frame. The media data between the extra request playing point and the key frame before the playing point can ensure that the jumping to any playing point can be decoded normally, and the condition that the frame jumping occurs because the frame can not be decoded when the playing point corresponds to the common frame is avoided.

Case 2) the video frame corresponding to the play point is a key frame, and the first key frame is: a key frame corresponding to the play point, that is, a key frame whose decoding time is aligned with the play point time, which is searched from the time of the media data (that is, a corresponding relationship between the sequence number represented by the media information and the decoding time of the frame); the second key frame of the two key frames is: key frames in the media file that are decoded later in time than the first key frame.

In case 2), the media data to be acquired is defined by aligning the key frames of the playing points, so that on the premise that the playing points can be correctly decoded, unnecessary media data acquisition is reduced to the greatest extent, occupation of connection and traffic is reduced, and real-time performance of non-media playing services in the webpage is ensured.

In some embodiments, the network request sent by the player to the server carries the offset and the capacity of the media data between the two requested key frames, so that the server extracts the media data starting from the offset and conforming to the capacity from the media file and returns the media data to the player. Therefore, before sending the network request, the player needs to determine the offset and capacity of the media data in the media file according to the media information (i.e. the position of the video/audio frame, the offset, the decoding time, etc.) identified from the metadata of the media file. And media information is first identified from the metadata of the media file before determining the offset and the size.

Next, the player identification media information will be explained. In some embodiments, the player may identify media information from the media file by: and according to the set offset and the set capacity, requesting data in the media file corresponding to the set offset and the set capacity (namely data requesting fixed capacity) from the server, identifying metadata in a metadata container from the data returned by the server, and analyzing the identified metadata to obtain media information for describing the media data packaged in the media data container of the media file.

The set capacity can be obtained according to the statistics of the capacities of the file type container and the metadata container of the existing media file, so that the set capacity can cover the sum of the capacities of the file type container and the metadata container of the set proportion (such as all) media files, and when the packaging structure of the media files is the file type container, the metadata container and the media data container which are packaged in sequence, the metadata packaged in the complete metadata container can be obtained through one request, the occupation condition of connection during network transmission is saved, and the condition that the response is delayed due to the fact that connection cannot be used in non-media playing services in a webpage due to connection occupation is avoided.

Taking an example that a media file is an MP4 file, metadata packaged in a metadata container acquired by a player is binary data packaged in a moov box in an MP4 file, and when a package structure of an MP4 file is a fytp box, a moov box, and an mdat box packaged in sequence, a set capacity can be obtained by statistics according to the ftyp box and moov box capacities of an existing MP4 file, so that the set capacity can cover the sum of the binary data of the ftyp box and the moov box of the MP4 file with a set proportion (such as all), and it is ensured that complete binary data can be included in the moov box requested from a server at one time in most cases.

In some embodiments, the player obtains the size of the file type container by reading the container header, knows the type and size of the next container by reading the second container header, and indicates that the binary data requested from the server by the set offset and size contains the metadata encapsulated in the metadata container when the second container type is the metadata container and the size of the returned binary data is not less than the sum of the size of the file type container and the size of the metadata container; when the type of the second container is the metadata container and the volume of the returned binary data is smaller than the sum of the volume of the file type container and the volume of the metadata container, it indicates that the binary data requested from the server by the set offset and volume does not contain the metadata packaged in the metadata container. When the binary data requested by the player from the server through the set offset and the set capacity does not contain the metadata in the complete metadata container, the player needs to read the capacity of the container from the binary data returned by the server, calculate the offset and the capacity of the metadata container according to the head of the metadata container, carry the calculated offset and the calculated capacity in a network request to request the metadata from the server, and the server starts to read the binary data from the offset calculated in the media file according to the request, wherein the read binary data conforms to the calculated capacity, and returns the data to the player.

For example, the player reads the volume of the container from the binary data returned by the server, and calculates the offset and the volume of the metadata container according to the header of the metadata container, which involves the following two cases:

Case 1) when the type of a container read from the remaining binary data (i.e., data other than the binary data of the file type container among the returned binary data) is a metadata container and the capacity of the remaining binary data is smaller than the capacity of the metadata container, calculating a difference between the capacity of the metadata container and the capacity of the remaining binary data as a new capacity of a secondary request, and requesting the binary data from the server a second time with the sum of the offset and the capacity of the primary request as a new offset;

Case 2) when the type of the container read from the remaining binary data is a media data container, the sum of the capacity of the media data container and the file type container capacity is calculated as a new offset of the secondary request, and the binary data is requested for the second time from the server at a set capacity (which may be an empirical value capable of covering the capacity of the metadata container).

Taking the media file as an MP4 file as an example, the binary data requested by the player from the server through the set offset and capacity does not include the binary data of the complete moov box, at this time, the player needs to read the type and capacity of the container from the binary data returned by the server, and determine the offset and capacity of the moov box in the MP4 file;

The binary data of the MP4 file, the initial byte always corresponds to the ftyp box, the binary data of the fytp box is identified from the returned binary data, the length of the ftypbox can be known from the header of the ftypbox, so that the binary data of the next box is read from the rest binary data according to the specified length of the header, and the following cases are included according to the type of the container represented by the header:

1) When the type of the container read from the remaining binary data (i.e., the data of the returned binary data excluding the binary data of the fytp box) is moov box and the capacity of the remaining binary data is not less than the capacity of the moov box, obtaining, from the server, moov data in the MP4 file starting with the offset of the moov box in the MP4 file and conforming to the capacity of the moov box in the MP4 file, according to the determined offset and capacity;

2) When the type of the container read from the remaining binary data is moov box and the capacity of the remaining binary data is less than the capacity of the moov box, calculating a difference value between the capacity of the moov box and the capacity of the remaining binary data as a new capacity of a secondary request, and requesting the binary data for a second time from the server with the sum of the offset and the capacity of the first request as the new offset of the secondary request;

3) When the type of the container read from the remaining binary data is the mdat box, the sum of the capacity of the mdat box and the capacity of the ftyp box is calculated as a new offset of the secondary request, and the binary data is requested for the second time from the server at the set capacity.

Therefore, no matter what packaging structure the media file is, namely, no matter what packaging sequence of the file type container, the metadata container and the media data container in the media file is, the player can be guaranteed to obtain the metadata in the metadata container from the server by two requests at most, and the metadata obtaining efficiency is improved.

For example, for an MP4 file, the binary data returned by the server, according to the package specification of the MP4 file, a piece of binary data starting from zero bytes corresponds to the ftyp box, and according to the package specification of the header of the box, the size (i.e., length) of the ftyp box and the size of the complete MP4 file can be read from the header of the ftyp box; assuming that the capacity of the ftyp box is a (in bytes), reading the header information of the subsequent container from a +1 to obtain the type and capacity of the subsequent container, and if the ftyp box is followed by the moov box by reading and the capacity of the remaining binary data (the capacity of the set capacity-ftyp box) is greater than the capacity of the moov box, indicating that the complete binary data of the moov box has been retrieved, extracting the metadata in the moov box from the remaining binary data according to the offset and capacity of the moov box.

After the player obtains the metadata encapsulated in the metadata container from the server, analyzing the nested structure of the child container in the metadata container, and reading the binary data in each child container according to the nested structure of the child container; and analyzing the media information of the media data represented by each sub-container from the read binary data. In practical applications, the media information may include information such as offset, capacity, decoding time, etc. of video frames and/or audio frames in the media file.

taking a media file as an MP4 file as an example, the metadata container is a moov box, as shown in fig. 2, it can be seen that mvhd box and track box are encapsulated in the moov box, wherein information such as creation time, modification time, time measurement scale, playable time length, default volume, etc. of the MP4 file can be obtained by analyzing binary data of the mvhd box; the moov box includes a plurality of track boxes, records description information specific to each media track, for example, for a video track, a plurality of sub-containers are nested in multiple layers in the video track, and based on the nested structure of the video track, the corresponding binary data is parsed to obtain video frame information of the MP4 file and corresponding picture information.

In some embodiments, the player may parse the acquired metadata to obtain the media information by: sequentially analyzing binary data corresponding to the standard length of the container head in the binary data of the metadata container to obtain the container type of a sub-container in the metadata container and the length of the container data of the sub-container; and calling a parser with a type corresponding to the container type of the sub-container, and sequentially parsing binary data corresponding to the length of the container data in the unresolved data to obtain the media information represented by the container data.

The player is used for solving the problem that a plurality of sub-containers are nested in the metadata container, the offset of each reading of binary data is the sum of the lengths of the identified sub-containers, and the length of the read binary data conforms to the standard length of the container header, so that the type and the length of the currently processed sub-container can be analyzed.

For example, when reading for the first time, the binary data is read from zero bytes of the binary data of the metadata container, and the length of the read binary data conforms to the specified length of the container header, so that the type and length of the first sub-container can be parsed; and in the second reading, the binary data is read by taking the length of the first read sub-container as an offset, and the length of the read binary data conforms to the specified length of the container header, so that the type and the length of the second sub-container can be analyzed.

The binary data is read in the mode, the condition of backspacing caused by multi-reading can not occur, the condition of secondary reading caused by less reading can not occur, and the analysis efficiency and the accuracy can be ensured.

In some embodiments, a typical container type nested in a metadata container is pre-marked for indicating whether the container is directly used for packaging binary data or is further packaged with a container, for example, a container is further packaged with a mark such as mvhd box, audio track box, and video track box shown in fig. 2, and a container is directly packaged with binary data with a mark such as stts box, stsd box shown in fig. 2.

Setting parsers corresponding to the container types one by one for the container types marked as directly encapsulating the binary data, wherein the parsers are used for parsing the represented media information according to the binary data; comparing the container type of the parsed sub-container with the container type of the pre-marked sub-container involves the following two cases.

Case 1) when it is determined through comparison that the container type of the child container is pre-marked and is pre-marked for directly encapsulating binary data, invoking a parser corresponding to the container type of the child container, and parsing the container data in the child container through the parser to obtain the media information represented by the container data.

Case 2) when it is determined through comparison that the container type of the sub-container is pre-marked and is pre-marked for continuously packaging containers, recursively analyzing the binary data corresponding to the sub-container according to the canonical length of the container header in the media file until the container type of the container packaged in the sub-container is pre-marked and is pre-marked for directly packaging the binary data, invoking an analyzer corresponding to the container type of the container packaged in the sub-container, analyzing the binary data byte by byte, where the length of the analyzed binary data corresponds to the length of the container data of the container packaged in the sub-container, to obtain the media information represented by the container data of the container packaged in the sub-container.

In some embodiments, a method for recording media information during parsing a metadata container is described, where binary data corresponding to a canonical length of a container header in binary data of the metadata container is sequentially parsed to obtain a container type of a child container in the metadata container, an object is created according to a nesting relationship between the child container and an attributed container and a nesting relationship between the child container and an encapsulated container, and when the container type of the child container is pre-marked to be used for directly encapsulating the binary data, an array including the media information is stored in the object created corresponding to the child container, where the stored media information is represented by the container data of the child container.

For example, in fig. 2, when the type of the parsed sub-container is stts box, since the stts box is pre-marked as direct package binary data, an array including media information is stored in an object created corresponding to the stts box, where the media information is duration information represented by container data of the stts box.

In some embodiments, the manner of recording the nesting relationship between the child containers in the process of parsing the metadata container is described in that when binary data corresponding to a canonical length of a container header in binary data of the metadata container is sequentially parsed to obtain a container type of the child container in the metadata container, if the container type is pre-marked as directly encapsulating binary data, the parsed child container is recorded in the invoked parser; setting the recorded instances of the child containers into child container attributes, wherein the child container attributes are included in the containers to which the child containers belong, and are used for describing the nesting relationship between the child containers and the belonged containers.

For example, in fig. 2, when the type of the parsed sub-container is stsd box, since stsd box is pre-marked as directly encapsulating binary data, stsd box is recorded in the parser corresponding to the stsd box, an instance of stsd box is set to the stbl box sub-container attribute, and so on, and finally a plurality of sub-containers nested in stbl box, such as stsd box, stts box, stsc box, etc., are recorded in the sub-container attribute of stsd box.

in some embodiments, when it is determined through the comparison that the container type of the sub-container is not pre-marked, or the container type of the sub-container is pre-marked to directly encapsulate binary data but a parser of a corresponding type is not called, the binary data corresponding to the parsed sub-container is ignored, and according to the length of the sub-container, a part of the binary data corresponding to a next sub-container is skipped to continue parsing.

in practical application, a user-defined container type can appear in a media file, the progress of the overall analysis of a metadata container can not be influenced in a skipping mode, and meanwhile, when the container type of the metadata container changes, the latest metadata container can be compatible and analyzed quickly by adding, deleting and modifying analyzers of corresponding types, and the media file has the advantages of being flexible and quick to upgrade.

Based on the above description of media information identification, the following description is directed to determining the offset and capacity of media data in a media file based on the identified media information, and in some embodiments, the player may determine the offset and capacity of media data in the media file by: determining, based on the identified media information, an offset and a capacity in the media file of video frames of the media data (i.e., video frames between the first key frame and the second key frame), and an offset and a capacity in the media file of audio frames aligned with the video frames; determining the offset and the capacity of a target interval (an interval consisting of the minimum offset and the maximum capacity) including the video frame and the audio frame according to the determined offset and the capacity; the target interval comprises the video frame and the audio frame.

Here, the alignment manner of the audio frame and the video frame in the embodiment of the present disclosure is explained: the method comprises the steps of positioning audio frames with synchronous time at video frames by taking the video frames as a reference according to the starting time and the duration of media data, ensuring that the decoding starting time of the first audio frame in the media data is not later than that of the first video frame, and the decoding time of the last audio frame is not earlier than that of the last video frame, so that the problem of inconsistent video and audio durations in media files can be solved, synchronous audio playing can be ensured when each frame of video is played, and the phenomenon that the existing picture has no sound can be avoided.

Next, the offset amount and the capacity of the determination target section will be explained: the method comprises the steps that the position of a video frame in a metadata container is located through the offset and the capacity of the video frame between a first key frame and a second key frame in two key frames in a media file, the position of an audio frame in the metadata container is located through the offset and the capacity of the audio frame aligned with the video frame in the media file, and an interval formed by the upper limit and the lower limit of the position is taken as a target interval, namely an interval formed by the minimum offset and the maximum capacity; the offset and the capacity corresponding to the upper limit of the position are the offset and the capacity corresponding to the upper limit of the target interval, and the offset and the capacity corresponding to the lower limit of the position are the offset and the capacity corresponding to the lower limit of the target interval. In practical applications, the target interval is the minimum interval for storing video frames and audio frames in the media data container of the target resolution media file, for example: and the offset of the video frame between the first key frame and the second key frame at the position of the target resolution media file corresponds to [ a, b ] (addresses are in ascending order), the offset of the audio frame at the position of the target resolution media file corresponds to [ c, d ] (addresses are in ascending order), and then the interval formed by the upper limit and the lower limit of the position is [ min (a, c), max (b, d) ]. Therefore, the player sends a network request carrying the offset and the capacity of the target interval to the server to request the media data of the target interval, the server extracts the media data in the media file based on the offset and the capacity of the target interval and then returns the media data of the target interval at one time, secondary acquisition is not needed, the request times of the player are reduced, and the processing efficiency is improved.

Step 703 constructs a segmented media file for independent decoding based on the requested media data.

Specifically, the server receives a network request of the player and then analyzes the network request to obtain an offset and a capacity corresponding to the media data requested by the player, and extracts the media data which starts from the offset and accords with the capacity from the media file based on the offset and the capacity.

After the server extracts the media data, the segmented media file can be constructed by the following method: the server calculates the metadata of the level of the segmented media file according to the media information of the media data, and then fills the metadata of the level of the segmented media file and the media data according to the packaging format of the segmented media file to obtain the segmented media file.

In some embodiments, the server does not perform conversion of the segmented media file for all media files in the non-streaming media format requested by the player, for example, the server may perform conversion only for a specific media file (e.g., a hot spot file), the server stores an identifier of a media file to be converted (e.g., a hot spot file), the network request carries the identifier of the media file, the server obtains the identifier of the media file after parsing the network request, determines whether the media file is the media file to be converted based on the identifier of the media file, extracts media data and constructs the segmented media file when the media file is determined to be the media file to be converted, and does not construct the segmented media file for the extracted media data if the media file corresponding to the media data requested by the player is determined not to be the media file to be converted based on the identifier of the media file.

In some embodiments, the server does not segment the construction of the media file for all of the media data in the media file, e.g., the server only segments the construction of the media file for media data of a particular portion of the media file (e.g., the second half of the media file). The network request carries the offset and the capacity of the media data in the media file, and the offset and the capacity are used for positioning the position of the media data in the media file by the server based on the offset and the capacity; and when the server confirms that the media data requested by the player is the media data to be converted in the media file based on the position obtained by positioning, constructing a segmented media file based on the extracted media data, and if the server confirms that the media data requested by the player is not the media data to be converted based on the position obtained by positioning, directly returning the media data without constructing the segmented media file.

In some embodiments, the network request may further carry authentication information for the server to perform authentication of user validity, for example, the authentication information may be login information (user name, password) of the user, the server performs authentication on the user validity based on the login information of the user after analyzing the network request, and when the server passes the authentication of the user validity based on the authentication information, the server returns a segmented media file constructed based on the extracted media data.

and explaining the segmented media file obtained after filling the metadata and the media data of the segmented media file level according to the packaging format of the segmented media file. In some embodiments, referring to fig. 8, fig. 8 is an alternative flow chart of packaging segmented media files provided by the disclosed example, which will be described in conjunction with the steps shown in fig. 8.

Step 801 fills data representing the type and compatibility of a segmented media file into a file type container of the segmented media file.

For example, taking as an example an FMP4 file packaged to form a package structure as shown in fig. 4, the type and length of a container (representing the entire length of the ftyp box) are filled in the header of the file type container of the FMP4 file, that is, the ftyp box, and data (binary data) representing that the file type is FMP4 and a compatible protocol is generated by filling in the data portion of the ftyp box.

step 802 populates metadata representing a file level of a segmented media file into a metadata container of the segmented media file.

In some embodiments, the metadata describing the media data required to fill the nested structure is calculated from the nested structure of the metadata container in the segmented media file, based on the media data to be filled into the encapsulation structure of the segmented media file.

Still taking fig. 4 as an example, metadata representing the file level of the FMP4 file is calculated and filled into a metadata container (i.e., moov box) of the FMP4, in which three containers of mvhd, track, and video extension (mvex) are nested.

Wherein, the metadata packaged in the mvhd container is used for representing the media information related to the playing of the segmented media file, including the position, the duration, the creation time, the modification time, and the like; the sub-containers nested in the track container represent references and descriptions of corresponding tracks in the media data, for example, a container (denoted as tkhd box) in which characteristics and overall information (such as duration and width) describing the tracks, and a container (denoted as mdia box) in which media information (such as information of media type and sample) of the tracks are nested in the track container.

Step 803, correspondingly filling the extracted media data and the metadata describing the media data into a media data container and a metadata container of a segment level in a segment container of the segmented media file.

In some embodiments, one or more segments (fragments) may be encapsulated in a segmented media file, and for media data to be filled, one or more segmented media data containers (i.e., mdat boxes) of the segmented media file may be filled, and a segment-level metadata container (denoted as moof box) is encapsulated in each segment, wherein the filled metadata is used to describe the media data filled in the segment, so that the segments can be independently decoded.

In conjunction with fig. 4, for example, the media data to be filled is filled into 2 segments of the packaging structure of the FMP4 file, and each segment is filled with the media data; the metadata that needs to be filled into the metadata container (i.e., moof box) of the segmentation level of the corresponding segment is calculated and correspondingly filled into the child containers nested in the moof box, wherein the head of the moof box is called moof box, and the filled binary data is used to indicate the type of the container as "moof box" and the length of the moof box.

In one embodiment of filling data into the corresponding container in steps 801 to 803, when the filling operation is performed, a write operation function of a calling class completes writing and merging of binary data in the memory buffer of the child container, and returns an instance of the class, and the returned instance is used for merging the child container and the child container with the nested relationship.

as an example of the stuffing data, a class MP4 for implementing a package function is established, and each sub-container in the segmented media file is packaged as a static method of class Stream; establishing class streams for realizing binary data operation functions, wherein each class Stream provides 0 with a memory buffer area for storing binary data to be filled; converting multi-byte decimal data to be padded into binary data by a static method provided by Stream; merging and filling binary data to be filled into the sub-containers in the memory buffer area through a write operation function provided by the Stream-like instance; the static method provided by Stream returns a new Stream instance, and the merging of the current child container and other child containers with nested relation can be realized.

Step 804, sending the segmented media file to the media element of the webpage through the media source expansion interface of the webpage, where the segmented media file is used for playing the media element following the playing point where the resolution switching event occurs.

Step 704, sending the segmented media file to the media element of the web page through the media source extension interface of the web page. And the segmented media file is used for playing the media element at the playing point when the resolution switching event occurs continuously. In some embodiments, the sending, by the player through the media source extension interface of the web page, the segmented media file to the media element of the web page for playing may include: the player adds the segmented media file to the media source object in the MSE interface; calling MSE to create a virtual address corresponding to the media source object; and transmitting a virtual address to the media element of the webpage, wherein the virtual address is used for playing the media element by taking the media source object as a data source. The media element may be a Video element and/or an Audio element of a web page, and the media element acquires the media source object through the virtual address to play.

Referring to fig. 9, fig. 9 is an optional schematic diagram of a player playing a segmented Media file through a Media Source extension interface of a web page according to the embodiment of the present disclosure, where when the player receives a play event of the Media file in a play window (corresponding to the play window) of the web page, the player creates a Media Source object by performing a Media Source method through MSE; executing an addSource buffer method packaged in a media source expansion interface to create a buffer of a MediaSource object, namely a Source buffer (Source buffer) object, wherein one MediaSource object has one or more Source buffer objects, and each Source buffer object can be used for corresponding to a playing window in a webpage and is used for receiving a segmented media file to be played in the window.

In the process of playing the media file, a Parser (Parser) in the player continuously constructs a new segmented media file by parsing newly acquired media data, and adds the segmented media file to a SourceBuffer object of the same MediaSource object by executing an appdbuffer method of the SourceBuffer object.

and after the player adds the constructed segmented media file to the media source object in the media resource expansion interface, calling the media resource expansion interface to create a virtual address corresponding to the media source object. For example, the player executes the createObjectURL method encapsulated in the media source extension interface, and creates a virtual address, i.e. a virtual Uniform Resource Locator (URL), of the corresponding media source object, in which the Blob-type segmented media file is encapsulated.

in addition, the player sets the MediaSource object as the source (src) attribute of the virtual URL, i.e., binds the virtual URL with a media element in the web page, such as a video/audio element, which is also referred to as associating the media source object to the media element in the web page.

in the embodiments of the present disclosure, the segmented media file added to the media source object is also: a currently playing segmented media file. For example, when the segmented media file 1 is played currently, and the subsequent segmented media files 2 and 3 are already constructed, the constructed segmented media files 2 and 3 are added to the Source Buffer of the MSE for preloading, and correspondingly, the first key frame of the two key frames corresponding to the media data acquired by the player is the first key frame appearing after the segmented media file 1.

For the virtual address passed by the player to the media element of the web page, the player includes a statement for calling the media element to play the virtual URL, for example: < audio > virtual URL. When the webpage explains the corresponding statement in the player embedded in the webpage, the media element of the webpage reads the segmented media file from the SourceBuffer object bound by the virtual URL, and the segmented media file is decoded and played.

The following describes a process in which the player converts the MP4 file into the FMP4 file and plays the web page through the media source extension interface.

Referring to fig. 10, fig. 10 is a schematic diagram of converting an MP4 file provided by the embodiment of the present disclosure into an FMP4 file and playing the file through a media source extension interface, where the player requests to obtain partial media data in an MP4 file from a server based on a real address (http:// www.toutiao.com/a/b. MP4) of the media file, for example, data with a decoding time in a given time period for a subsequent playing point.

The player constructs an FMP4 file based on the acquired media data, and then adds the FMP4 file to a Source buffer object corresponding to the MediaSource object, because the virtual URL is bound to the MediaSource object, when the player calls the code of the audio/video element to be executed, the audio/video element reads a new FMP4 file which is added continuously from the Source buffer object of the MediaSource object, decodes the new FMP4 file, and realizes the continuous playing of the media file. The media elements of the webpage are used for acquiring the media source object based on the virtual URL, so that the media file is played, and the media data is not acquired based on the real address of the media file, so that the real address of the media file is protected.

Next, taking an example that the player is embedded in a web page, and the player plays the MP4 file using the HTML5 Video element + audio element of the web page, the playback control method of the embodiment of the disclosure will be described, and according to the implementation of MP4, the method can be easily applied to other non-streaming media formats. Fig. 11 shows an optional flowchart of the play control method provided in the embodiment of the present disclosure, and referring to fig. 11, the play control method provided in the embodiment of the present disclosure includes:

Step 1101: the player requests the data in the fixed-capacity MP4 file from the server according to the set offset and capacity.

The player sends a data request carrying the set offset and capacity to the server to obtain binary data which starts from zero bytes in the MP4 file and conforms to the set capacity. Taking the case that the MP4 file package structure includes fytp box, moov box and mdat box packaged in sequence as an example, the set capacity may be obtained by statistics of the ftyp box and moov box capacities of the existing MP4 file, so that the set capacity can cover the sum of the ftyp box and the moov box of the MP4 file with a set ratio (e.g., all), and it is ensured that complete moov box binary data can be requested from the server at one time. And if the complete moov data is not obtained through the primary request, recalculating the offset and the capacity, and further performing secondary request.

Step 1102: the player receives the data returned by the server and identifies the media information of the MP4 file from the data returned by the server.

the media information of the MP4 file includes information of offset, capacity, decoding time, etc. of video/audio frames in the MP4 file.

In some embodiments, the player may implement the identification of the media information of the MP4 file by: recognizing binary data of the fytp box from the data returned by the server, and reading the type and the capacity of the container from the rest binary data; when the type of the read container is moov box and the capacity of the remaining binary data is not less than that of the moov box, the media information is parsed from the remaining binary data. Here, for the binary data returned by the server, the first piece of binary data is necessarily corresponding to the ftyp box, and according to the package specification of the ftyp box, the capacity (i.e. length) of the ftyp box and the capacity of the complete MP4 file can be read; for example, the capacity a (in bytes) of the ftyp box, the header information of the subsequent container is read from a +1 to obtain the type and capacity of the container, if the container is a moov box and the capacity (set to be the capacity of the ftyp box) is greater than the capacity of the moov box, which indicates that the complete binary data of the moov box has been retrieved, the binary data can be parsed according to the packaging structure to restore the media information.

In some embodiments, when the binary data returned by the server does not include complete moov data, reading the capacity of the container from the acquired binary data, and determining the offset and the capacity of the moov box in the MP4 file; according to the determined offset and capacity, when the type of the container read from the remaining binary data is moov box and the capacity of the remaining binary data is not less than the capacity of the moov box, obtaining, from the server, moov data in the MP4 file, starting with the offset of the moov box in the MP4 file and conforming to the capacity of the moov box in the MP4 file; when the type of the container read from the remaining binary data is moov box and the capacity of the remaining binary data is less than the capacity of the moov box, calculating a difference between the capacity of the moov box and the capacity of the remaining binary data as a new capacity of the secondary request, and requesting the binary data to the server a second time with the sum of the offset and the capacity of the primary request as a new offset.

in practical applications, there are cases where the packaging structure of the MP4 file is fytp box, mdat box, moov box packaged sequentially, and when the type of the container read from the remaining binary data is mdat box, the sum of the capacity of mdat box and the capacity of moov box is calculated as a new offset of the secondary request, and the binary data is requested for the second time from the server at the set capacity.

Step 1103: during the playing process of the MP4 file by the player through the web page, two key frames in the MP4 file are positioned according to the identified media information and the current playing point.

In the embodiment of the present disclosure, the player plays with the media data (including at least video data, and may further include audio data) between two key frames as a loading unit, that is, the player plays the MP4 file by loading the media data between two key frames, there may be only a common frame between two key frames, that is, two key frames are adjacent key frames, and there may also be other key frames between two key frames.

Taking the example of reaching the playing point of the MP4 file by jumping, the player locates the first key frame as follows: the first key frame of the MP4 file with decoding time before the playing point locates the second key frame as: key frames in the MP4 file that are decoded later in time than the first key frame. Here, the video frame of the media file corresponding to the playing point includes two cases, i.e., a normal frame and a key frame, and when the video frame corresponding to the playing point is just the key frame, the first key frame of the MP4 file whose decoding time is before the playing point is the key frame corresponding to the playing point, i.e., the first key frame in the media data requested by the player at this time is the key frame corresponding to the playing point.

Two key frames in the player location MP4 file include: and determining the offset and the capacity of the first key frame and the second key frame based on the identified media information and the current playing point, and further requesting the media data between the first key frame and the second key frame from the server based on the offset and the capacity.

step 1104: media data between two located key frames is requested from the server.

In actual implementation, the player sends a network request to the server to request media data between two key frames located in the MP4 file, where the network request carries an offset and a capacity of a target interval corresponding to the two key frames.

Here, the player locates the position of the video frame in mdat by the offset and the capacity of the video frame between the first key frame and the second key frame in the MP4 file, locates the position of the audio frame in mdat by the offset and the capacity of the audio frame aligned with the video frame in the MP4 file, takes a section formed by an upper limit and a lower limit of the position as a target section, the offset and the capacity corresponding to the upper limit of the position as the offset and the capacity corresponding to the upper limit of the target section, and the offset and the capacity corresponding to the lower limit of the position as the offset and the capacity corresponding to the lower limit of the target section.

For example, the duration of a media file is 120 seconds, wherein the media file comprises a plurality of key frames, when a given time period is 20 th to 40 th seconds, according to the mapping relationship between the decoding time of a frame and the sequence number of the frame, firstly, whether a key frame with the decoding time right at the 20 th second exists is searched, and if the key frame with the decoding time right at the 20 th second exists, the key frame with the decoding time right at the 20 th second is used as a first key frame; if not, a key frame which is earlier than the 20 th second in decoding time and is closest to the 20 th second of starting time is searched as the first key frame.

Secondly, whether a key frame with decoding time just at the 40 th second exists is searched, and if yes, the key frame with decoding time just at the 40 th second is used as a second key frame; if not, searching a key frame which is later than the 40 th second in decoding time and is closest to the 40 th second as a second key frame.

by searching the key frame in the video frame, the condition that the starting time corresponds to a common frame and the frame skipping can not be played can be avoided, and meanwhile, the acquisition of useless data is reduced to the maximum extent, and the flow is saved during network transmission.

Step 1105: the server extracts media data between the two key frames in the MP4 file and constructs a segmented media file in FMP4 format based on the extracted media data.

In practical implementation, the server calculates metadata at the level of the segmented media file according to the media information of the media data, and then fills the metadata at the level of the segmented media file and the media data according to the packaging format of the segmented media file in the FMP4 format to obtain the segmented media file in the FMP4 format.

Step 1106: returning the constructed segmented media file to the player.

the server realizes the conversion from the MP4 format file to the segmented media file in the FMP4 format, and pushes the segmented media file to the front-end player, the front-end player does not need to convert, the playing load is small, the hardware capability of the terminal does not need to be limited, and the endurance of the terminal is ensured.

Step 1107: the player adds the segmented media file to the media source object in the MSE interface.

Step 1108: the player passes the virtual address to the media element of the web page.

The virtual address is used for the media element (video element + Audio element) to play video by using the media source object as a data source.

In summary, the embodiments of the present disclosure have the following beneficial effects:

1) the method has the advantages that the segmented media files converted from the media data in the media files in the non-streaming media format are sent to the media elements of the webpage for decoding and playing through the media source expansion interface of the webpage, so that the media files in the non-streaming media format are played through the webpage, the limitation that the files in the non-streaming media packaging format can be played independently after being downloaded completely is overcome, and meanwhile, the media files in the MPEG-4 format are played efficiently in a low storage space occupation mode.

2) in the playing process of the player embedded in the webpage, when the resolution ratio is switched, the pictures can be switched seamlessly, and the phenomenon of generating a black screen and influencing the normal use of a user is avoided.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present disclosure, and all the changes or substitutions should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A method for playing media files in a webpage by switching resolutions is characterized by comprising the following steps:

Receiving a resolution switching event when a player embedded in a webpage plays an original resolution media file;

Responding to the resolution switching event, and requesting media data in a target resolution media file to be switched;

wherein, the original resolution media file and the target resolution media file adopt a non-streaming media packaging format;

Constructing a segmented media file for independent decoding based on the requested media data;

And sending the segmented media file to a media element of the webpage through a media source expansion interface of the webpage, wherein the segmented media file is used for playing the media element at a playing point when the media element is connected with the resolution switching event.

2. The method of claim 1, wherein requesting media data in a target resolution media file comprises:

Determining two key frames in the target resolution media file based on the time of the video frame represented by the media information of the target resolution media file;

Decoding time of the two key frames is end point time of a given time interval, and the given time interval is used for continuing a playing point of the original resolution file;

requesting media data in the target resolution media file based on a location of media data represented by the media information in the target resolution file, a decoding time of the requested media data being located in the given time period.

3. the method of claim 2,

The duration of the given time period is less than or equal to a pre-loading duration, and the pre-loading duration is less than the playing duration of the target resolution media file.

4. The method of claim 1, wherein constructing segmented media files for independent decoding based on the requested media data comprises:

calculating metadata corresponding to the media data, wherein the calculated metadata carries media information for supporting decoding of the media data;

And filling the calculated metadata and the media data between the two key frames into an encapsulation structure of the segmented media file to obtain the corresponding segmented media file.

5. The method of claim 1, wherein sending the segmented media file to the media element of the web page via a media source extension interface of the web page comprises:

adding the constructed segmented media file to a media source object in the media resource extension interface;

Creating a virtual address corresponding to the media source object;

And transmitting the virtual address to the media element of the webpage, wherein the virtual address is used for playing the media element by taking the media source object as a data source.

6. The method according to any one of claims 1 to 5, further comprising:

when the resolution switching event is received, continuing playing the segmented media file based on the original resolution until,

And constructing a segmented media file with the target resolution, and sending the segmented media file to the media elements of the webpage through the media source expansion interface.

7. an apparatus for playing media files at a switched resolution in a web page, the apparatus comprising:

the event receiving module is used for receiving a resolution switching event when the player embedded in the webpage plays the original resolution media file;

The data request module is used for responding to the resolution switching event and requesting the media data in the target resolution media file to be switched;

A segment construction module for constructing a segmented media file for independent decoding based on the requested media data;

And the media playing module is used for sending the segmented media file to the media element of the webpage through a media source expansion interface of the webpage, wherein the segmented media file is used for playing the media element at a playing point when the media element is connected with the resolution switching event.

8. the apparatus of claim 7,

The data request module is further configured to determine two key frames in the target resolution media file based on the time of the video frame represented by the media information of the target resolution media file;

the data request module is further configured to request media data in the target-resolution media file based on a location of the media data represented by the media information in the target-resolution file, where a decoding time of the requested media data is located in the given time period.

9. The apparatus of claim 8,

10. The apparatus of claim 7,

the segment construction module is further configured to calculate metadata corresponding to the media data, where the calculated metadata carries media information for supporting decoding of the media data;

And the segmentation construction module is used for filling the calculated metadata and the media data between the two key frames into an encapsulation structure of the segmented media file to obtain the corresponding segmented media file.

11. The apparatus of claim 7,

The event receiving module is further used for adding the constructed segmented media file to a media source object in the media resource expansion interface;

The event receiving module is further configured to create a virtual address corresponding to the media source object;

The event receiving module is further configured to transmit the virtual address to a media element of the web page, where the virtual address is used for the media element to play with the media source object as a data source.

12. The apparatus of any one of claims 7 to 11, further comprising:

an information playing module, configured to continue playing the segmented media file based on the original resolution until the resolution switching event is received,

And the segmentation construction module constructs a segmented media file with the target resolution and transmits the segmented media file through the media source expansion interface.

13. An apparatus for playing media files in a web page with a switched resolution, comprising:

a memory for storing executable instructions;

a processor, configured to execute the executable instructions to implement the method for playing media files in the web page with switched resolutions according to any one of claims 1 to 6.

14. a storage medium storing executable instructions for implementing a method for playing a media file at a switched resolution in a web page according to any one of claims 1 to 6 when executed.